Surgical robotic user input apparatus having optical fiber-based intrinsic sensors

ABSTRACT

A surgical robotic user input apparatus has a fiber optic cable with a handheld user input device attached at one end, and a connector attached at another end. Multiple intrinsic sensors, such as fiber Bragg grating sensors, are in the fiber optic cable. The intrinsic sensors are used to detect a pose of the handheld user input device. Other embodiments are also described and claimed.

This nonprovisional patent application claims the benefit of the earlierfiling date of provisional application No. 62/639,969 filed Mar. 7,2018.

An embodiment of the invention relates to user input devices for thecontrol of surgical robotic arms and tools. Other embodiments are alsodescribed.

BACKGROUND

In surgical robotic systems for teleoperation purposes, user inputdevice tracking provides accurate sensing of user intent and control astable and robust motion of a surgical robotic arm and an attachedsurgical robotic tool. Mechanisms for spatial tracking of a user inputdevice known as electromagnetic trackers have been used, but do notfulfill the precision (e.g., noise problem) and latency requirements ofsurgical robotic systems. If the resulting information is not free ofnoise, drift and immune to magnetic interference from the environment,the error of the pose estimate of the user input device may generateundesired movement of the arm or tool, especially when sub-mm (forposition or translation) and sub-degree (for orientation) precision maybe needed. To reduce noise, the signal from the user input devices canbe filtered, though at the expense of introducing latency, which also isnot desirable.

SUMMARY

A surgical robotic user input apparatus and related method, in variousembodiments, are described. Various embodiments include a fiber-opticcable with intrinsic sensors that is attached to a user input device.

In one embodiment, a surgical robotic user input apparatus has ahandheld user input device (handheld UID) that is attached to afiber-optic cable. The fiber-optic cable has intrinsic sensors. Thefiber-optic cable has a first end with a connector that may be pluggablewith (e.g., into) a connector of a stationary site such as a userconsole, and a second end. The hand-held user input device is attachedto the second end of the fiber-optic cable. The intrinsic sensors areused to detect a pose of the handheld UID. The pose includes athree-dimensional position of the handheld UID and a rotation ororientation of the handheld UID, e.g., relative to the stationary firstend.

One embodiment of the invention is a method of operating a surgicalrobotic user input apparatus, for tracking a user input device. Themethod includes sending first light into a fiber-optic cable that hasintrinsic sensors, and receiving second light from the fiber opticcable. The first light may be modified by the intrinsic sensors. A poseof a hand-held user input device, that is attached to a second end ofthe fiber-optic cable, is determined by processing the sensed orreceived second light. The pose is a three-dimensional position and arotation or orientation. The determined pose is continually updated,resulting in the tracking of the user input device.

The above summary does not include an exhaustive list of all aspects ofthe present invention. It is contemplated that the invention includesall systems and methods that can be practiced from all suitablecombinations of the various aspects summarized above, as well as thosedisclosed in the Detailed Description below and particularly pointed outin the claims filed with the application. Such combinations haveparticular advantages not specifically recited in the above summary.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention are illustrated by way of example andnot by way of limitation in the figures of the accompanying drawings inwhich like references indicate similar elements. It should be noted thatreferences to “an” or “one” embodiment of the invention in thisdisclosure are not necessarily to the same embodiment, and they mean atleast one. Also, in the interest of conciseness and reducing the totalnumber of figures, a given figure may be used to illustrate the featuresof more than one embodiment of the invention, and not all elements inthe figure may be required for a given embodiment.

FIG. 1 is a pictorial view of an example surgical robotic system in anoperating arena.

FIG. 2 depicts an example of a surgical robotic user input system oruser console, with a handheld user input device whose pose is trackedusing fiber Bragg grating sensors.

FIG. 3 is an information flow diagram for the surgical robotic userinput system of FIG. 2.

FIG. 4 depicts a sensing component for the surgical robotic user inputsystem of FIG. 2.

FIG. 5 depicts inline fiber Bragg grating sensors.

FIG. 6 depicts diagonal bias fiber Bragg grating sensors.

FIG. 7 is a block diagram of a processing unit and an optical sensinginterrogator for use in the surgical robotic user input system of FIG.2.

FIG. 8 is a flow diagram of a method of operating a surgical roboticuser input system.

DETAILED DESCRIPTION

Several embodiments of the invention with reference to the appendeddrawings are now explained. Whenever the shapes, relative positions andother aspects of the parts described in the embodiments are notexplicitly defined, the scope of the invention is not limited only tothe parts shown, which are meant merely for the purpose of illustration.Also, while numerous details are set forth, it is understood that someembodiments of the invention may be practiced without these details. Inother instances, well-known circuits, structures, and techniques havenot been shown in detail so as not to obscure the understanding of thisdescription.

Referring to FIG. 1, this is a pictorial view of an example surgicalrobotic system 1 in an operating arena. The robotic surgical system 1includes a user console 2, a control tower 3, and one or more surgicalrobotic arms 4 located at a surgical platform 5, e.g., a table, a bed,etc. The surgical robotic system 1 can incorporate any number ofdevices, tools, or accessories used to perform surgery on a patient 6.For example, the surgical robotic system 1 may include one or moresurgical tools 7 used to perform surgery. A surgical tool 7 may be anend effector that is attached to a distal end of a surgical robotic arm4, for executing a surgical procedure.

Each surgical tool 7 can be manipulated manually and/or roboticallyduring the surgery. For example, the surgical tool 7 may be a tool usedto enter, view, or manipulate an internal anatomy of the patient 6. Inan embodiment, the surgical tool 6 is a grasper used to grasp tissue ofthe patient. The surgical tool 6 may be controlled manually, by abedside operator 8; or it may be controlled robotically, by actuatedmovement of the surgical robotic arm 4 to which it is attached. Thesurgical robotic arms 4 are shown as a table-mounted system, but inother configurations the surgical robotic arms 4 may be mounted in acart, ceiling or sidewall, or in another suitable structural support.

Generally, a remote operator 9, such as a surgeon or other operator, mayuse the user console 2 to remotely manipulate the surgical robotic arms4 and/or the attached surgical tools 7, e.g., tele-operation. The userconsole 2 may be located in the same operating room as the rest of thesurgical robotic system 1, as shown in FIG. 1. In other environmentshowever, the user console 2 may be located in an adjacent or nearbyroom, or it may be at a remote location, e.g., in a different building,city, or country. The user console 2 may comprise a seat 10,foot-operated controls 13, one or more handheld user input devices, UID14, and at least one user display 15 that is configured to display, forexample, a view of the surgical site inside the patient 6. In theexample user console 2, the remote operator 9 is sitting in the seat 10and viewing the user display 15 while manipulating a foot-operatedcontrol 13 and a handheld UID 14 in order to remotely control thesurgical robotic arms 4 and the surgical tools 7 (that are mounted onthe distal ends of the surgical robotic arms.)

In some variations, the bedside operator 8 may also operate the surgicalrobotic system 1 in an “over the bed” mode, in which the beside operator8 (user) is now at a side of the patient 6 and is simultaneouslymanipulating a robotically-driven tool (end effector as attached to thesurgical robotic arm 4), e.g., with a handheld UID 14 held in one hand,and a manual laparoscopic tool. For example, the bedside operator's lefthand may be manipulating the handheld UID to control a surgical roboticcomponent, while the bedside operator's right hand may be manipulating amanual laparoscopic tool. Thus, in these variations, the bedsideoperator 8 may perform both robotic-assisted minimally invasive surgeryand manual laparoscopic surgery on the patient 6.

During an example procedure (surgery), the patient 6 is prepped anddraped in a sterile fashion to achieve anesthesia. Initial access to thesurgical site may be performed manually while the arms of the surgicalrobotic system 1 are in a stowed configuration or withdrawnconfiguration (to facilitate access to the surgical site.) Once accessis completed, initial positioning or preparation of the surgical roboticsystem 1 including its surgical robotic arms 4 may be performed. Next,the surgery proceeds with the remote operator 9 at the user console 2utilizing the foot-operated controls 13 and the UIDs 14 to manipulatethe various end effectors and perhaps an imaging system to perform thesurgery. Manual assistance may also be provided at the procedure bed ortable, by sterile-gowned bedside personnel, e.g., the bedside operator 8who may perform tasks such as retracting tissues, performing manualrepositioning, and tool exchange upon one or more of the surgicalrobotic arms 4. Non-sterile personnel may also be present to assist theremote operator 9 at the user console 2. When the procedure or surgeryis completed, the surgical robotic system 1 and the user console 2 maybe configured or set in a state to facilitate post-operative proceduressuch as cleaning or sterilization and healthcare record entry orprintout via the user console 2.

In one embodiment, the remote operator 9 holds and moves the UID 14 toprovide an input command to move a robot arm actuator 17 in the surgicalrobotic system 1. The UID 14 may be communicatively coupled to the restof the surgical robotic system 1, e.g., via a console computer system16. The UID 14 can generate spatial state signals corresponding to thepose and movement of the UID 14, e.g. position and orientation of thehandheld housing of the UID, and the spatial state signals may be inputsignals to control a motion of the robot arm actuator 17. The surgicalrobotic system 1 may use control signals derived from the spatial statesignals, to control proportional motion of the actuator 17. In oneembodiment, a console processor of the console computer system 16receives the spatial state signals and generates the correspondingcontrol signals. Based on these control signals, which control how theactuator 17 is energized to move a segment of the surgical robotic arm4, the movement of a corresponding surgical tool that is attached to thearm may mimic the movement of the UID 14. Similarly, interaction betweenthe remote operator 9 and the UID 14 can generate for example a gripcontrol signal that causes a jaw of a grasper of the surgical tool 7 toclose and grip the tissue of patient 6.

Surgical robotic system 1 may include several UIDs 14, where respectivecontrol signals are generated for each UID that control the actuatorsand the surgical tool (end effector) of a respective surgical roboticarm 4. For example, the remote operator 9 may move a first UID 14 tocontrol the motion of an actuator 17 that is in a left surgical roboticarm, where the actuator responds by moving linkages, gears, etc., inthat surgical robotic arm 4. Similarly, movement of a second UID 14 bythe remote operator 9 controls the motion of another actuator 17, whichin turn moves other linkages, gears, etc., of the surgical roboticsystem 1. The surgical robotic system 1 may include a right surgicalrobotic arm 4 that is secured to the bed or table to the right side ofthe patient, and a left surgical robotic arm 4 that is at the left sideof the patient. An actuator 17 may include one or more motors that arecontrolled so that they drive the rotation of a joint of the surgicalrobotic arm 4, to for example change, relative to the patient, anorientation of an endoscope or a grasper of the surgical tool 7 that isattached to that arm. Motion of several actuators 17 in the samesurgical robotic arm 4 can be controlled by the spatial state signalsgenerated from a particular UID 14. The UIDs 14 can also control motionof respective surgical tool graspers. For example, each UID 14 cangenerate a respective grip signal to control motion of an actuator,e.g., a linear actuator, that opens or closes jaws of the grasper at adistal end of surgical tool 7 to grip tissue within patient 6.

In some aspects, the communication between the surgical platform 5 andthe user console 2 may be through a control tower 3, which may translateuser commands that are received from the user console 2 into roboticcontrol commands that transmitted to the surgical robotic arms 4 on thesurgical platform 5. The control tower 3 may also transmit status andfeedback from the surgical platform 5 back to the user console 2. Thecommunication connections between the surgical platform 5, the userconsole 2, and the control tower 3 may be via wired and/or wirelesslinks, using any suitable ones of a variety of data communicationprotocols. Any wired connections may be optionally built into the floorand/or walls or ceiling of the operating room. The surgical roboticsystem 1 may provide video output to one or more displays, includingdisplays within the operating room as well as remote displays that areaccessible via the Internet or other networks. The video output or feedmay also be encrypted to ensure privacy and all or portions of the videooutput may be saved to a server or electronic healthcare record system.

In one embodiment, a clutch freezes the surgical robotic arm(s) 4 and/orits attached surgical tool 7, so that one or a combination of thosecomponents does not respond to movements of an associated one or moreUIDs 14. In some versions, the user, e.g. a surgeon, presses a clutchbutton or touches a sensing area (or alternatively, releases a clutchbutton or ceases to touch a sensing area) to disconnect the controlinput of the UID 14 from the surgical robotic system, and can repositionthe UID 14 within the workspace without causing movement of anyactuator. The clutch could be implemented as a mechanical device, ahardware electronic module, software executing on a processor, orcombination of these. Sensing for user input to engage or disengage theclutch, operate or freeze the surgical robotic arm(s) 4 and/or surgicaltool 7, could be made by a capacitive sensing or other clutch-taskedinput device attached to or integrated with a UID 14. In some versions,if the user ceases to hold the UID 14, e.g., by setting the UID down,dropping the UID, etc., this is sensed by the clutch-tasked input deviceof the UID 14, and the system in response freezes one or morecomponents, through the clutch, such as discussed above.

Fiber Bragg grating (FBG) sensors are optical fibers that are sensitiveto strain, which can stem from mechanical and thermal stresses. Thesensor is a piece of optical fiber with periodically placed refractivegratings in them. Fiber Bragg gratings may be achieved by inducingperiodic changes in the refractive index of the fiber core that act likea mirror for a well determined wavelength called Bragg wavelength. Thedistance between the refractive gratings is correlated to the lighttransmitted or reflected inside the fiber core. Stretching orcompressing the fiber changes this distance between the gratings, andtherefore modulates the spectrum of light traveling inside the fiber.The wavelength of light that gets reflected from the refractive indicesinside the fiber core is named “the Bragg wavelength”. By monitoring theBragg wavelength, the strain of the fiber can be predicted, and thenturned into temperature, force or shape information depending on theapplication. FBG sensors are used for structural monitoring (attachingfibers on vehicle transport bridges and buildings to help predict theonset of critical events and structural failure/life), tracking ofcatheters and snake-like robotic manipulators (the shape of flexiblemedical instruments can be estimated while operating inside the humanbody and when no other means of visualization is feasible), temperaturesensing (FBGs are integrated in ablation tools to measure temperaturedirectly at the tip of the instrument in order to keep it at a desiredlevel), and finally for force sensing (by attaching FBG sensors onmedical instruments, tool-tissue interaction forces can be sensed at thetip of the instrument).

Various embodiments described herein include handheld user input devicesthat are controlled by the user for use in robotic surgery, i.e.surgical robotics, and a tracking system and method to determine thepose of these devices using fiber Bragg grating technology. In additionin some embodiments, there may be a means of determining the userapplied pressure to the handheld user input devices. This system andmethod are used to enable a surgeon's input during teleoperation toperform remote control of surgical robotic instruments. For instance,FIG. 2 illustrates part of the user console 2—see FIG. 1—which is acomponent of a teleoperative robot-assisted surgical platform, andcomprises one or more visualization devices (e.g. monitor 206), asurgeon chair 208, arm rests 210 on which the surgeon rests her armsduring use of the robotic surgical system, a handheld user input device202, connector 206 for coupling a fiber optic cable 204 to the arm rest210 or the chair 208, an optional internal connection 212 between thefiber optic cable 204 and an optical sensing interrogator 214 (where thelatter supports one or more input FBG sensor channels), and a processingunit (not shown in FIG. 2 but see FIG. 7). While only one input FBGsensor channel is shown, there may be more than one, e.g. one for a lefthand UID and another for a right hand UID.

In the example surgical robotic user input system or user console ofFIG. 2, a pose of the handheld user input device is tracked using fiberBragg grating sensors. Fiber Bragg grating sensors are attached to andbetween the handheld user input device 202 and the arm rest 210, in thefiber optic cable 204. Generally, fiber Bragg grating sensors areconsidered intrinsic sensors, as they are part of the optical fiberinside of which a FBG is formed and do not require an electric powersupply. The use of intrinsic sensors, without electrical wires andelectrical or electronic components, makes some versions of the userinput device 202 and fiber-optic cable 204 sterilizable, for example inan autoclave. In further embodiments, instead of or in addition to anFBG sensor, other types of optical fiber based intrinsic sensors couldbe used, such as Fabry-Perot interferometric sensors, and other types ofinterferometric sensors.

In this exemplary setup, the user (e.g. a surgeon) sits in a chair 208and can view the monitor 206. The user's arms can be rested on thearmrests 210, and the user holds one or more handheld user input devices202 in each hand. One or more intrinsic fiber Bragg grating sensors areintegrated into the fiber optic cable 204 that extends from the handhelduser input device 202 to the arm rests 210. The fiber optic cable 204 isoptically coupled to the optical sensing interrogator 214 which enablesthe FBG sensor data acquisition (see FIG. 3). Optionally, a fiber opticconnection 212 enables the remote measurement of the FBG sensor data.

This setup allows the user to move the handheld user input device 202freely to any position and in any orientation in space, while the systemcontinuously computes the exact pose of the UID. The information flowduring a sample operation is shown in FIG. 3.

FIG. 3 is an information flow diagram for the robotic surgical userinput system of FIG. 2. User actions 302 cause position and statuschanges 304 on the handheld user input device 202, which influence thefiber Bragg grating sensors' spectral response. Based on the common anddifferential modes extracted from the spectral response 306, temperaturecompensated 308 shape and status estimates 310 are computed. Thecomputed information can be used to control 312 a robotic device such asa surgical robotic arm and its attached tool for teleoperation, which ismonitored by the user via visual feedback 314.

As the surgeon moves the handheld user input devices, the shape of thefiber(s) changes, influencing varying strain on the FBG sensors. Inaddition, there can be additional user inputs, such as squeezing (seeFIG. 4) or push button, inducing strain onto other FBG fiber(s) withinthe handheld user input device. The applied strain on FBGs lead tochanges in the fibers' spectral response, which is captured by theoptical sensing interrogator. The shift in the Bragg wavelength of eachsensor can be analyzed to obtain the common mode (e.g., average ofsensor readings on each fiber core at the same position) anddifferential mode (deviation of each sensor output from the common mode)readings. The common mode can be used to predict ambient temperaturechanges, and cancel out undesired thermal drift in the sensors'response. The differential mode of sensors can be used to compute theshape of the connecting fiber, and therefore the position andorientation of the handheld user input device. The information fromother FBG sensor(s) inside the handheld user input device can similarlydefine if the user has released or squeezing the handheld user inputdevice. The computed information can then be used to generate motioncommands for the robotic manipulator. In a further embodiment, themeasurement of pressure or button click by the user's fingers can alsobe done by electronics, e.g., a printed circuit board (PCB), that iswithin the housing of the user input device 202 or that is electricallyconnected to the user input device 202, instead of or in addition to aFBG sensor.

To track the spatial and status information from the handheld user inputdevices, a sample architecture for integrating FBG sensors is shown inFIG. 4.

FIG. 4 depicts a sensing component for the robotic surgical user inputsystem of FIG. 2. Shape sensing FBG sensors 414 are affixed in the fiberoptic cable 410 between the frontal end of a handheld user input device402 and the connector 412 site. The frontal end of the user input device402 can function as a housing 416 for electronics or other sensors.Located inside the housing 416 is a pressure-sensitive FBG sensor 422,which is normally kept stretched by the spring loaded 418 piston 420.The rest of the handheld UID 402 is elastic, for example a squeeze bulb404. By squeezing the elastic portion with fingers 406, 408, the usercan apply variable pressure on the piston 420, which induces varyingcompression of the FBG sensor 422 inside the housing. In a furtherembodiment, pressure or a button click is sensed by a switch, touchpad,touchscreen or other touch-sensing electromechanical or electronicdevice attached to or integrated with the handheld UID 402, or induces avarying release of a pre-tensioned FBG sensor 422 inside the housing.

With reference to FIGS. 2-4, for tracking the position and orientationof the handheld user input device, fiber(s) are rigidly attached to thefrontal end of the handheld user input device 202, 402 and connected tothe optical sensing interrogator 214. As the user moves and rotates thehandheld user input device 202, 402 in space, this connection willchange its shape, which will be captured by the FBGs. The frontal end ofthe handheld user input device 202, 402 can be used to house othersensor(s). An example application is to use another FBG sensor 422 witha spring loaded 418 plunger 420 inside the proximal end of the handhelduser input device 402. In this design, the proximal end can be anelastic enclosure held between the fingers 406, 408. By squeezing theelastic enclosure, the user can generate varying pressure, which willmove the spring loaded 418 plunger 420 up and down, tensioning orcompressing the FBG sensor 422. This enables capturing the status of thehandheld user input device 402 precisely and quickly.

FIG. 5 depicts inline fiber Bragg grating sensors 502. Arranged inlinerelative to a longitudinal axis 504 of the fiber optic cable 204connected to the handheld user input device 202 (see FIG. 2), thesefiber Bragg grating sensors 502 respond to positional changes such asvertical or lateral displacement and bending of the fiber optic cable204. Only a small number of the fiber Bragg sensors 502 are shown in thedrawing, generally embodiments will have many more of these. Two opticalfibers 506, with fiber Bragg sensors 502, are shown for detectingdisplacement in the vertical direction, through differential modeanalysis, and two more optical fibers 508, with fiber Bragg sensors 502,are shown for detecting displacement in the lateral direction, alsothrough differential mode analysis. Further embodiments could have moreoptical fibers with fiber Bragg sensors 502, for redundancy, accuracyimprovement, or more directly sensing displacement in diagonaldirections.

FIG. 6 depicts diagonal bias fiber Bragg grating sensors 602. Arrangedat a nonzero, non-vertical angle, i.e., a diagonal bias, relative to thelongitudinal axis 504 of the fiber optic cable 204 connected to thehandheld user input device 202 (see FIG. 2), these fiber Bragg sensors602 respond to rotational changes such as twisting of the fiber opticcable 204. Only a small number of the fiber Bragg sensors 602 are shownin the drawing, generally embodiments will have many more of these. Oneoptical fiber 604 with fiber Bragg sensors 602 is shown spiraling aroundthe fiber optic cable 204 as if a right-hand thread of a bolt or screw,and another optical fiber 606 with fiber Bragg sensors 602 is shownspiraling around the fiber optic cable 204 as if a left-hand thread.Rotation or twist of the fiber optic cable 204 in a given direction willgenerally compress fiber Bragg sensors 602 in one of the optical fibersand extend fiber Bragg sensors 602 in the other of the optical fibers,and vice versa for rotation in an opposing direction. Furtherembodiments could have more optical fibers with fiber Bragg sensors, forredundancy or accuracy improvement.

FIG. 7 is a block diagram of a processor-based optical sensinginterrogator for use in the surgical robotic user input system of FIG.2. The optical sensing interrogator 214 and processing unit 706 areshown as separate items, but could be integrated into a single unit inone embodiment. An optical sending unit 702 sends broad spectrum lightout to the fiber optic cable 204 with the fiber Bragg grating sensors.Some of this light is spectrally modified and reflected back by thefiber Bragg grating sensors, and received by the optical sensing unit704. In the processing unit 706, a processor 708 may be programmed byvarious software modules that are stored in memory, to perform analysisof the light received by the optical sensing unit 704. Note that atleast some of the actions of the processor in executing these modulescan alternatively be implemented in dedicated and separate hardwareunits. In some embodiments, the processing unit 706 is part of acomputer system in the user console 2 or in the tower 3—see FIG. 1. Acommon mode analyzer 710 determines common mode modification of thelight. A differential mode analyzer 712 determines differential modemodification of the light. A temperature compensation unit 714determines temperature changes, and corrects for thermal drift inreadings of the sensors, based on the common mode analysis. Adisplacement analyzer 716 determines three-dimensional displacementalong the fiber optic cable, based on the differential mode analysis. Anaxis rotation analyzer 718 determines rotation along the fiber opticcable, such as rotation along the longitudinal axis of the fiber opticcable, or alternatively rotation relative to an axis of the user inputdevice 202, 402 or another axis for another coordinate system, based onthe differential mode analysis. A surgical robotic handheld user inputdevice pose determination unit 720 determines Cartesian XYZ position andXYZ rotation, or pose, of the handheld user input device, based on thedisplacement analysis and axis rotation analysis. Alternatively, insteadof Cartesian coordinates for the handheld user input device pose, polarcoordinates or other coordinate systems could be used in variations. Ahandheld user input device pressure determination unit 722 determinespressure in the handheld user input device, based on the differentialmode and/or common mode analysis, as appropriate to the arrangement ofsensor(s) in the handheld user input device coupled to receive pressure.

FIG. 8 is a flow diagram of a method of operating a surgical roboticuser input system. The method is performed by a processor-based opticalsensing interrogator with separate or integrated programmed processor asdescribed with reference to FIG. 7, in one embodiment. In an action 802,first light is sent to a first end of a fiber optic cable. The fiberoptic cable has optical fibers with intrinsic sensors. In someembodiments, the intrinsic sensors are fiber Bragg grating sensors.

In an action 804, second light is received from the first end of thefiber optic cable. In an action 806, a pose of a handheld user inputdevice is determined. The handheld user input device is attached to thesecond end of the fiber optic cable. Determination of the pose is basedon the second light, as the first light modified by the intrinsicsensors.

While certain embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat the invention is not limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those of ordinary skill in the art. For example, while FIG. 4depicts a handheld user input device that transmits finger pressure to aspring-loaded piston compressing a fiber Bragg grating sensor, otherarrangements for the handheld user input device are possible (e.g.,levers, tension, a user input device without pressure sensing, othertypes of sensors, other arrangements of sensors, and various shapes forthe handheld user input device). Where determining a shape of one of theintrinsic sensors is described, it should be appreciated that shapes ofmultiple intrinsic sensors can be determined. The description is thus tobe regarded as illustrative instead of limiting.

What is claimed is:
 1. A surgical robotic user input apparatus,comprising: a fiber optic cable having a plurality of intrinsic sensorstherein, a first end with a connector and a second end; a handheld userinput device (handheld UID) attached to the second end of the fiberoptic cable, wherein the handheld UID comprises a squeeze bulb havingtherein a pressure coupling to a pressure sensing one of the pluralityof intrinsic sensors; and the plurality of intrinsic sensors beingconfigured to modify propagating light in the fiber optic cable todetect a pose of the handheld UID, the pose comprising athree-dimensional position of the handheld UID and a rotation of thehandheld UID.
 2. The surgical robotic user input apparatus of claim 1,further comprising: an optical sensing interrogator arranged to coupleto the connector of the fiber optic cable.
 3. The surgical robotic userinput apparatus of claim 1, wherein the plurality of intrinsic sensorscomprises a plurality of fiber Bragg grating sensors.
 4. The surgicalrobotic user input apparatus of claim 1, wherein the plurality ofintrinsic sensors comprises a plurality of interferometric sensors. 5.The surgical robotic user input apparatus of claim 1, wherein the fiberoptic cable comprises: a first plurality of optical fibers having afirst plurality of intrinsic sensors, arranged inline with respect to alongitudinal axis of the fiber optic cable; and a second plurality ofoptical fibers having a second plurality of intrinsic sensors, wrappedor woven at a bias with respect to the longitudinal axis of the fiberoptic cable.
 6. The surgical robotic user input apparatus of claim 1wherein the fiber optic cable comprises a bundle of single-core opticalfibers or a multi-core optical fiber, and wherein the plurality ofintrinsic sensors are distributed discretely along a length of thesingle-core fibers or multi-core optical fiber.
 7. The surgical roboticuser input apparatus of claim 1, wherein the handheld UID comprises: thesqueeze bulb having gas, liquid, gel or semisolid material therein; adiaphragm, piston or plunger within the squeeze bulb and exposed to thegas, liquid, gel or semisolid material; and a spring-loaded couplingfrom the diaphragm, piston or plunger to one or more of the plurality ofintrinsic sensors, to compress or tension the one or more of theplurality of intrinsic sensors in response to finger or hand pressure onthe squeeze bulb.
 8. The surgical robotic user input apparatus of claim1, wherein the handheld UID and fiber optic cable include no electricaldevices and are sterilizable.
 9. The surgical robotic user inputapparatus of claim 1, further comprising: an optical sensinginterrogator, arranged to couple to the fiber optic cable and transmitlight to the plurality of intrinsic sensors, and to detect lightreturned from the plurality of intrinsic sensors; and a programmedprocessor to determine, based on the detected light, pressure exerted onthe handheld UID, the pose of the handheld UID, and ambient temperaturechanges.
 10. The surgical robotic user input apparatus of claim 1,further comprising: a touch-sensing device attached to or integratedwith the handheld UID.
 11. A method of operating a surgical robotic userinput apparatus, the method comprising: sending first light into a fiberoptic cable having a plurality of intrinsic sensors; receiving secondlight from the fiber optic cable, wherein the second light comprises thefirst light modified by the plurality of intrinsic sensors; anddetermining a pose, comprising a three-dimensional position and arotation, of a handheld user input device (handheld UID) attached to thefiber optic cable, based on the detected second light, whereindetermining the three-dimensional position of the handheld UID is basedon differential mode analysis of the first light modified by a firstsubset of the plurality of intrinsic sensors, wherein the first subsetis oriented inline with a longitudinal axis of the fiber optic cable.12. The method of claim 11, further comprising: determining relativepressure or pressure change of the handheld UID, based on the secondlight received from the fiber optic cable.
 13. The method of claim 11,further comprising: determining common mode modification of the firstlight, in the second light; and determining differential modemodification of the first light, in the second light.
 14. The method ofclaim 11, further comprising: determining temperature change, based ondetecting common mode modification of the first light, in the secondlight; and correcting for thermal drift in readings of the plurality ofintrinsic sensors, based on the determined temperature change.
 15. Themethod of claim 11, further comprising: determining a shape of one ofthe plurality of intrinsic sensors, based on detecting differential modemodification of the first light, in the second light, wherein thedetermining the pose is based on the determining the shape.
 16. Themethod of claim 11, wherein the determining the pose comprisesdifferential mode analysis of the second light as the first lightmodified by a plurality of fiber Bragg grating sensors that are a subsetof the plurality of intrinsic sensors.
 17. The method of claim 11,wherein the determining the pose comprises differential mode analysis ofthe second light as the first light modified by a plurality ofinterferometric sensors that are a subset of the plurality of intrinsicsensors.
 18. The method of claim 11, wherein the determining the pose ofthe handheld UID comprises: determining the rotation of the handheld UIDbased on differential mode analysis of the first light modified by asecond subset of the plurality of intrinsic sensors, wherein the secondsubset is oriented at a bias relative to the longitudinal axis of thefiber optic cable.
 19. The method of claim 11, further comprising:determining a value of a compression or extension of one of theplurality of intrinsic sensors that is arranged to react to pressure ofthe handheld UID, through analysis of the first light modified by theintrinsic sensor.
 20. The method of claim 11, further comprising:sending data regarding the pose of the handheld UID to a roboticcontroller in a surgical robotics system.